Allegro MicroSystems has added a 48 V power management integrated circuit and several position-sensing devices to its robotics portfolio. The components target the electrical and mechanical demands of tightly packaged joints in humanoid robots and other articulated machines, where power distribution, motor position feedback and fault detection must fit into limited space. Allegro is also working with Canadian developer Sarcomere Dynamics on gripping systems, giving the product range a named application partner.
The A81481 draws on a 48 V distribution supply to provide regulated lower-voltage outputs close to sensors and control electronics. It combines two buck converters with five low-dropout regulators in a 6 by 6 mm package, alongside diagnostics and a triple-watchdog architecture designed for safety-oriented systems. Integrating several functions into one device can reduce external components and board area compared with a design using multiple individual converters and supervisors.
Allegro claims its reference power management arrangement can reduce footprint and bill-of-materials cost by roughly 50 per cent. The comparison is specific to that part of the electronics design, not the cost or size of an entire robot. A finished machine also requires motors, mechanical transmissions, structural members, drives, batteries or a separate supply, communications and thermal management. Actual savings therefore depend on which components the A81481 replaces and the electrical demands of the joint or sensor module.
Using a 48 V supply can lower distribution current for a given power level compared with a bus operating at substantially lower voltage. Lower current reduces resistive losses in wiring with the same resistance, although it does not eliminate conversion losses or heat generated in the motors and drivers. Local power converters must provide stable rails while meeting requirements for electromagnetic compatibility, fault response and thermal limits in the confined volume of a moving actuator.
The A81481 includes watchdog functions intended to detect when expected control activity does not occur within a specified interval. Its diagnostics are described by Allegro as ASIL-D-capable, drawing on automotive functional safety design practices. Such building blocks can support a safety architecture, but the rating of an integrated circuit does not automatically make a complete humanoid robot safe or certified. Analysis of the complete system must establish diagnostic coverage, response paths and behaviour when a fault is detected.
Accurate joint feedback is equally important to servo control. Motor current and torque can create magnetic interference near a position sensor, while gear loading, bearing movement and manufacturing tolerances alter the spacing between parts. Allegro’s A17802 and A17803 inductive position sensors are designed to withstand stray fields and variations in the air gap through on-chip compensation and filtering. Their output still depends on a suitable target geometry, installation accuracy and calibration of the joint’s mechanical transmission.
The inductive approach is intended for joints carrying higher torque such as shoulders, hips and knees, where sensor packaging and mechanical robustness can become more demanding as actuators grow. A sensor that tolerates the qualified range of air-gap variation can simplify integration, but it cannot compensate for unlimited wear, backlash or misalignment. The controller also has to receive position data with sufficient accuracy and latency to maintain stable operation under load.
Robotic hands place greater emphasis on size. Allegro offers the CT310 tunnelling magnetoresistance, or TMR, angle sensor in a 2 by 2 mm package and reports sub-degree precision. The A33023 Hall-effect angle sensor is another compact solid-state option with low-latency operation and digital output choices. TMR and Hall devices sense magnetic fields through different mechanisms, so the target magnet, calibration, temperature behaviour and resistance to interference must be evaluated for each application.
Replacing a mechanical or optical encoder with a smaller magnetic device requires more than a comparison of package sizes. Finger mechanisms have short travel ranges, small bearings and tightly packed wiring, all of which can influence the actual signal. The controller must interpret that signal correctly through the motor’s operating range, including at low speed and under changing torque. Selection therefore depends on measurement performance, repeatability, fault diagnostics and the conditions established during joint testing.
Sarcomere Dynamics says it is integrating Allegro electronics into its Scorpion gripper and intends to expand the relationship to its ARTUS Dex robotic hand with 24 degrees of freedom. That programme is an identified collaboration, not evidence that every new device is already in volume use across commercial robots. Allegro has made product information and evaluation support available and plans to show the range at electronica 2026, where potential customers can assess the devices against their own actuator and control architectures.
